Patch "vfio/iommu_type1: Populate full dirty when detach non-pinned group" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    vfio/iommu_type1: Populate full dirty when detach non-pinned group

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     vfio-iommu_type1-populate-full-dirty-when-detach-non.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit c290d1d38541e98eca482d1cff5e66d8fe96be1b
Author: Keqian Zhu <zhukeqian1@xxxxxxxxxx>
Date:   Fri Jan 22 17:26:34 2021 +0800

    vfio/iommu_type1: Populate full dirty when detach non-pinned group
    
    [ Upstream commit d0a78f91761fcd837da1e7a4b0f8368873adc646 ]
    
    If a group with non-pinned-page dirty scope is detached with dirty
    logging enabled, we should fully populate the dirty bitmaps at the
    time it's removed since we don't know the extent of its previous DMA,
    nor will the group be present to trigger the full bitmap when the user
    retrieves the dirty bitmap.
    
    Fixes: d6a4c185660c ("vfio iommu: Implementation of ioctl for dirty pages tracking")
    Suggested-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
    Signed-off-by: Keqian Zhu <zhukeqian1@xxxxxxxxxx>
    Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 67e8276389951..a08b2cb4ec66e 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -236,6 +236,18 @@ static void vfio_dma_populate_bitmap(struct vfio_dma *dma, size_t pgsize)
 	}
 }
 
+static void vfio_iommu_populate_bitmap_full(struct vfio_iommu *iommu)
+{
+	struct rb_node *n;
+	unsigned long pgshift = __ffs(iommu->pgsize_bitmap);
+
+	for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
+		struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
+
+		bitmap_set(dma->bitmap, 0, dma->size >> pgshift);
+	}
+}
+
 static int vfio_dma_bitmap_alloc_all(struct vfio_iommu *iommu, size_t pgsize)
 {
 	struct rb_node *n;
@@ -2415,8 +2427,11 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
 	 * Removal of a group without dirty tracking may allow the iommu scope
 	 * to be promoted.
 	 */
-	if (update_dirty_scope)
+	if (update_dirty_scope) {
 		update_pinned_page_dirty_scope(iommu);
+		if (iommu->dirty_page_tracking)
+			vfio_iommu_populate_bitmap_full(iommu);
+	}
 	mutex_unlock(&iommu->lock);
 }